>> reporter: at that point, southwest flight 812 is cruising at 36,000 feet, around 500 miles per hour. the oxygen masks are deployed and the pilot knows he needs to get that jet to a lower altitude with or without permission. >> need like 10,000 feet. could you approve that? i'm doing it anyway. >> yes, approved. >> reporter: the plane needs to be below 10,000 feet because that is where the passengers can breathe without oxygen. now, they need to find a place to land soon. they want to turn around and fly to phoenix but it's too far. air traffic controllers suggest palm springs but the pilot has another idea. >> how far away from houma now.yuma right >> change of plans. going to yuma now.